Signal recording/reproducing method and apparatus, signal record medium and signal

ABSTRACT

A signal recording/reproducing method and apparatus, signal record medium and signal transmission/reception method and apparatus, whereby a signal recorded on a signal record medium can identified as being an original signal or a copied signal. A CPU  11  generates, at a pe-set time interval, an identification signal having a meaning at a pre-set time interval, and an identification signal addition circuit  3  adds the identification signal to the video signals and/or the audio signals. A sector forming circuit  5  and circuit components up to a recording/reproducing head  14  record the video signals and/or the audio signals and the ancillary identification signal on an optical disc  12.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. application Ser. No. 08/698,089, filed Aug.15, 1996.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a signal recording/reproducing method andapparatus for recording/reproducing signals on or from a signal record(recording, recordable or recorded) medium, a signal record mediumhaving signals recorded thereon, and a signal transmitting/receivingmethod and apparatus for transmitting/receiving signal over a signaltransmission medium.

2. Description of the Related Art

As a signal record medium for recording information signals, such asspeech or various sorts of data, such signal record medium for opticallyrecording the information signals, such as a compact disc for music or aCD-ROM employing the CD disc standard for data, is in widespread use.Recently, the standardization for a so-called digital video disc (DVD),as the next generation signal record medium, is also proceeding.

Meanwhile, the entire audio or video signals, for example, recorded onthe signal record medium, such as CD, CD-ROM or DAD, may be read out bya reproducing apparatus and duplicated on another signal record mediumcapable of signal recording and reproduction, such as a hard disc, andthe data thus copied on the hard disc may then be supplied to an encodersystem for the CD, CD-ROM or DAD for formulating a new CD, CD-ROM orDAD, in order to prepare a CD, CD-ROM or a DAD having recorded thereonthe same signals as those recorded on the original signal record medium.

If new signal recording media are produced in this manner one afteranother, it becomes impossible to discriminate whether the signalsrecorded on the signal record medium are original signals or copiedsignals. Of course, this problem is encountered not only in thedisc-shaped record medium, such as the CD or CD-ROM, but also in atape-shaped record medium or other signal recording media. It istherefore desirable that signals recorded on a given signal recordmedium can be identified to be original signals or copied signals.Although it has been practiced up to now to record in a pre-set area ofthe signal record medium the information specifying that originalsignals or copied signals have been recorded on the signal recordmedium, there lacks up to now a technique for identifying whether thesignal is the original signal or the copied signal based on the signalitself.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a signalrecord (recording, recordable or recorded) method and apparatus wherebythe signals to be recorded on a signal record medium can be identifiedto be original signals or copied signals.

It is another object of the present invention to provide a signalreproducing method and apparatus whereby the signals already recorded ona signal record medium can be identified to be original signals orcopied signals.

It is yet another object of the present invention to provide a signaltransmitting method and apparatus whereby it is possible to identify thetransmission hysteresis of transmitted signals.

With the signal recording method and apparatus and the signaltransmission method and apparatus of the present invention, anidentification signal relevant to the video signals and/or the audiosignals is inserted as a portion of the video signals and/or the audiosignals in a configuration of reducing the effect on the video signalsand/or the audio signals, and the video signals and/or the audiosignals, into which has been inserted the identification signal, arerecorded on a signal record medium or transmitted over a signaltransmission medium.

With the signal reproducing method and apparatus and the signalreceiving method and apparatus of the present invention, the videosignals and/or the audio signals reproduced from the signal recordmedium or transmitted over the signal transmission medium are received,and the identification signal, inserted as a portion of the videosignals and/or the audio signals, is detected from the reproduced orreceived signals.

The signal record medium of the present invention has recorded thereonsignals comprised of the video signals and/or the audio signals and anidentification signal which is relevant to the video signals and/or theaudio signals and which has been inserted as a portion of the videosignals and/or the audio signals in a configuration of reducing theeffect on the video signals and/or the audio signals.

According to the present invention, the meaningful identification signalis added to the video signals and/or the audio signals themselves inorder to permit identification of these signals.

That is, according to the present invention, the identification signalrelevant to the video signals and/or the audio signals is inserted as aportion of the video signals and/or the audio signals in a configurationof reducing the effect on the video signals and/or the audio signals andthe video signals and/or the audio signals, to which has been insertedthe identification signal as an ancillary signal, are recorded on asignal record medium or transmitted over a transmission medium. Thus,with the aid of the identification signal, it becomes possible toidentify whether the signal recorded on a signal record medium is anoriginal signal or a copied signal, while it also becomes possible tocomprehend the hysteresis of the received signal. In addition, theidentification signal, thus added to the video signals and/or the audiosignals, is effective to prevent unauthorized copying.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a typical waveform of audio signals.

FIG. 2 illustrates an embodiment in which an identification signal isappended to the least significant bit (LSB) of a 1-sample-16-bit timedomain audio PCM signals.

FIG. 3 shows an arbitrary pixel in a frame to which is appended anidentification signal.

FIG. 4 is a block circuit diagram showing an arrangement of anillustrative signal recording apparatus and an illustrative signalreproducing apparatus.

FIG. 5 shows an optical disc as an example of a signal record medium.

FIG. 6 is a block circuit diagram showing an example of appending anidentification signal during encoding for data compression.

FIG. 7 is a block circuit diagram showing an illustrative arrangement ofan encoding circuit for compression.

FIG. 8 illustrates a sequence interchanging operation.

FIG. 9 is a block circuit diagram showing an arrangement of appending anidentification signal to a video signal in an analog stage.

FIG. 10 is a block circuit diagram showing an arrangement of appendingan identification signal to an audio signal in an analog stage.

FIG. 11 is a schematic block circuit diagram showing an arrangement of atransmission apparatus.

FIG. 12 is a schematic block circuit diagram showing an arrangement of areception apparatus.

FIG. 13 is a block circuit diagram showing essential portions of signaltransmission/reception over a transmission channel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, preferred embodiments of the presentinvention will be explained in detail.

According to the present invention, an identification signal pertinentto the video signal and/or the audio signal is inserted as a part of thevideo signal and/or the audio signal in a configuration of reducing theeffect on the video signal and/or the audio signal.

An illustrative example of insertion of such identification signal ishereinafter explained.

If time-domain data, such as music signals, are digitized, “0”s and “1”sare randomly distributed in the least significant bits (LSBs) in suchdigital data. If only these LSBs are collected, the distribution of “0”sand “1”s are generally the normal distribution about 50% as center.

For example, if the audio signal waveform W as shown in FIG. 1 issampled and quantized to 1-sample-16-bit time domain audio PCM signalsshown for example in FIG. 2, the least significant bits (LSBs) of the1-sample-16-bit time domain audio PCM signals are handled statistically.

If 1,000 samples are handled as a statistic, the distribution of “0” and“1” deviates from a range of ¤62 about 500 as a center (438 or less and562 or more) in a state in which the level of significance is 0.01% andthere is a bias which is not a usual state.

Therefore, the state biased to “1” or “0” may be created by compulsorilyincreasing “1” or “0” in the LSBs of the sample data of the originalsignals for detection.

If, for a pre-set time width, or a certain time interval, the LSBs ofthe audio PCM signals of the respective samples are set for example to“0”, irrespective of whether the time interval is synchronous ornon-synchronous, the number of “0”s is statistically increased, with thenumber of “1”s being decreased. Conversely, if the LSBs are set to “1”,the number of “1”s is statistically increased, with the number of “0”sbeing decreased. Thus it becomes possible to represent one bit of thepertinent identification signal.

Most simply, the LSBs of the continuous 1,000 samples may compulsorilybe set to “1” or “0”. Although this simplifies detection, the LSBs of16-bit samples are used contiguously, the effective bits become 15 bits,thus deteriorating the signal. In addition, the signal tends to bealtered.

Thus it may be contemplated to set arbitrary 200 of 1000 consecutivesamples compulsorily to “1” or “0”. These arbitrary 200 samples may beconsecutive in an arbitrary position in the 1,000 samples, or may be atdiscontinuous random positions. If the samples are contiguous, they canbe detected easily. However, the risk of signal deterioration andalteration becomes higher.

If the arbitrary 200 samples in the contiguous 1,000 samples are setcompulsorily to “1” or “0”, the LSBs of the remaining 800 samples may beapproximated to the normal distribution. For example, if “1”s areintroduced into the 200 samples, the number of “1”s in the LSBs of theremaining 800 samples, if fluctuated, is comprised substantially in 400¤ 40. If 200 “1”s are added, the number of “1”s of the LSBs of the 1,000samples is 600 ¤ 40, with the level of significance being 0.01%. It maythus be seen that 1 bit of the identification signal is “1”. Similarly,by inserting “0” into the LSBs of the 200 samples, the 1 bit of theidentification signal may be associated with “0”. By compulsorilysetting the LSBs of the arbitrary 200 samples to “1” or “0” every 1,000samples of the audio PCM signals as main data, “1”s or “0”s of theidentification signals can be sequentially embedded in the main dataitself.

As more specified examples, the LSBs of the 200 samples are compulsorilyset to “1”s or “0”s at an interval of 5 samples of the 1,000 samples. Inthis case, since the original signals are not changed continuously, theeffect is small as compared to the case of embedding in LSBs ofcontiguous 200 samples. For detection, the number of “1”s or “0”s of theLSBs of the 1,000 samples may be counted. Alternatively, the 5-sampleperiod count may be performed in parallel for five series of differentphases to find out a series where drastic bias exists.

If the periodic position samples in the series of samples are used, theLSBs may be compulsorily set to “1”s or “0”s at an arbitrary sampleperiod such as 10 sample period. If the period is 10 samples, the LSBsof the 100 samples are modified in the 1,000 samples. However, bycounting the number of “1”s and “0”s of the LSBs of 10 series ofdifferent phases at 10-sample periods, the totality of 100 samples aredetected as “1” or “0” so long as there is no error, thus assuring highreliability. If “1”s or “0”s are compulsorily inserted into the LSBs, ate.g., 100 sample period, 10 of 1,000 samples are of the same value inthe 1,00 samples, so that detection can be achieved with somereliability. However, if the period is longer, the number of sampleseries for parallel counting is increased, so that it becomes necessaryto effect parallel counting in the LSBs of the 100 series of sampleshaving different phases. The number of samples that is handledstatistically is not limited to 1,000 but may be optionally set to 2,000or 10,000 samples.

It is also possible to embed plural sorts of identification signals inparallel. If the total number of samples handled statistically is 1,000,and “1”s or “0”s are compulsorily inserted at a period of 50 samples,plural sorts of identification signals can be inserted at differentphases in the 50-sample period. If, as a specified example, five sorts(channels) of the identification signals are embedded in differentphases, and these five sorts are embedded at equal intervals, the LSBsare compulsorily set to “1”s or “0”s at a period of 10 samples. Fordetection, LSBs of the 50 different sample series having differentphases are counted at 50 sample periods and a series in which only “1”sor “0”s are contiguously detected may be used as an identificationsignal. Of course, the number of samples or the number of sample periodsare not limited to 1000 samples or 50 samples, respectively.

It may also be conceived to handle the LSBs of the samples at periodicpositions in the sample series. That is, of 1,000 16-bit samples of theaudio PCM signals, sequentially taken out at, for example, five samplesas a period, 200 samples, may be arbitrarily taken out and compulsorilyset to “1”s or “0”s. In this case, the 1 bit of the identificationinformation is distributed in a range of contiguous 5,000 samples of theoriginal PCM data. Of the 1,000 samples of the 5-sample periods in the5,000 samples, 200 samples may be selected by taking 200 consecutivesamples, random 200 samples or 200 samples at a 5-sample period (theperiod being 25 samples for the entire samples).

If “1”s are inserted in the LSBs in the above examples, statistic biasmay be enlarged by modifying to “1”s only “0”s of the LSBs of theoriginal data.

In sum, if the LSBs of the audio PCM signal samples are set to, forexample, “0”, at a pre-set time interval, whether synchronously orasynchronously, the number of “0”s is statistically increased and thenumber of “1”s is correspondingly decreased, whereas, if the LSBs areset to “1” in the same manner, the number of “1”s is statisticallyincreased and the number of “0”s is correspondingly decreased.

Thus, if the LSBs, for example, of respective audio PCM samples are setto “0”s or “1”s at a pre-set time interval, it becomes possible toinsert an identification signal represented by one bit of “0” or “1” inthe above-mentioned 1-sample-16-bit audio PCM signals. The above pre-settime interval is preferably set so as not to produce alien hearingfeeling even if the “0”s or is are inserted in the LSBs.

Instead of inserting “0”s or “1”s at a pre-set time interval asdescribed above, it is also possible to insert an identification signalmade up of noise-like “0”s and “1”s having meaning in a certain timeinterval in, for example, the LSBs of respective samples in the pre-settime interval. If the LSBs of the respective samples are read with theabove time intervals as units, it becomes possible to take out theidentification signals from the LSBs in the respective samples in thetime interval. If the contents of the identification signal to beinserted into the above LSBs are modified at the above-mentioned timeinterval, it becomes possible to insert plural sorts of identificationsignals. It is however desirable to use the noise-like information asthe plural sorts of the identification signals in order to minimizeadverse psychoacoustic effects.

The identification signal may be inserted into bits other than the LSBs.In the case of audio signals, ill effects on the acoustic sense may beminimized by inserting the identification signal in the LSBs. Therefore,the identification signal is inserted in the present embodiment in theLSBs.

If the identification signal is inserted in the LSBs in low signal level(signal energy) portions of audio signals, there is a risk that additionof an identification signal even in the LSB produces outstanding alienpsychoacoustic feeling. For example, if the signal level corresponds to15 bits in terms of an absolute value level, a range from 0 to 32767 maybe represented, of which the MSB corresponds to 16384 and the LSBcorresponds to 1. If the LSB is intentionally modified for addition ofthe identification signal, and if the original signal level is 25000,for example, the effect of intentional change of the LSB is small.However, if the original signal level is 10, for example, the effect ofintentionally changing the LSB is no longer negligible. For avoidingsuch ill effect on the psychoacoustic sense, it is also possible to addthe identification signal only to the LSBs in the high signal level(signal energy) portion. In such case, it becomes necessary to detect ahigh signal level portion and to add the identification signal to theLSBs only in such high signal level portion. This can be achieved byoperating on the LSB only when “1”is set in, for example, the MSB.

In the low signal level portion temporally before and after the highsignal level portion, the masking effect on the time axis, that is theeffect of the low signal level portion being masked by the high signallevel portion, is in operation, so that addition of the identificationsignal can be done only in the masked portion. Similarly, if time-domainaudio signals are orthogonal-transformed into frequency-domain signals(frequency components) which are quantized, the masking effect on thefrequency axis, that is the effect in which low-energy frequencycomponents are masked by frequency components where the energy isstrongly concentrated, is in operation. In such case, the identificationsignal may be appended only to this masked low-energy frequencycomponents.

Although the above refers to audio signals, the same holds true forvideo signals. Since the LSB of an 8-bit luminance signal assumesstatistically random values, it becomes possible to increase or decrease“0”s or “1”s in the LSBs of the luminance signal. In the case of videosignals, insertion of “0”s or “1”s in the LSBs of the luminance signalsmay be on the pixel PX basis, line basis, field or frame basis, onmultiple frame basis or on the time basis, such as at an interval of onesecond. If the signal insertion is on the multi-frame basis, theidentification signal may be appended in certain pixel data of every30th frame. In the case of the video signals, such an interval ispreferably used in which as small effects on the visual sense aspossible will be produced by insertion of “0”s and “1”s in the LSBs.

In the case of the video signals, the identification signal may beinserted in bits other than the LSB. It is however desirable to insertthe identification signal in the LSBs since any adverse effects on thevisual sense may be minimized in the case of the video signals if theidentification signal is inserted in the LSBs.

In the case of video signals, as in audio signals, it is possible toinsert the identification signals, made up of noise-like “0”sand “1”s,having a meaning at a certain time width, in the LSBs as describedabove. Also, in the case of the video signals, plural sorts of theidentification signals may be inserted by varying the contents of theidentification signals inserted in, for example, the LSBs at a pre-settime interval. In inserting the plural sorts of the identificationsignals, the noise-like information which possibly affects visualcharacteristics to a lesser extent is preferably employed.

In the case of the video signals, if the identification signals areadded to a low signal level portion, the added signal tends to becomevisually outstanding. Therefore, the above identification signal may beadded only in the high signal level portion, as described above. Theidentification signal may be appended taking the masking effect asvisual characteristics into account.

According to the present invention, as described above, the number of“0”s or “1”s may be statistically increased or decreased in the LSBs oftime-domain audio PCM signals or video signals exhibiting strongtime-axis or frequency axis correlation by adding “0”s or “1”s in theseLSBs for supplementarily appending the identification signal other thanthe audio or video information.

If the identification signal is the information specifying that theaudio or video signals represent original audio or video signals, itbecomes possible to identify the audio or video signals to be originalsignals or copied signals, or to record copying hysteresis.

The identification signal may also be a maker ID, producer ID, formatterID, copying management information, such as copy inhibit/permit, or thekey information for encryption, instead of being the above-mentionedinformation specifying whether the signal is an original signal or acopied signal.

Meanwhile, the identification signal, annexed to the audio or videosignals, may also be such a signal as compulsorily sets a given domainto “0”s or “1”s, instead of being a statistically represented signal, asdescribed previously. That is, the identification signal compulsorilysetting a given domain to “0”s or “1”s, may also be a certain sort ofthe control signal, or may be used for prescribing and detecting an areacontaining these “0”s or “1”s.

An illustrative structure for realization of the above will now beexplained. First, an illustrative structure of appending theidentification signal to the video signals is explained.

FIG. 4 shows an illustrative arrangement of a signal recording apparatusfor recording video signals, to which the above identification signalhas been appended, on an optical disc 12, as a signal record medium(recording, recordable or recorded) of the present invention, and anillustrative arrangement of a signal reproducing apparatus forreproducing video signals, having the appended identification signal,from the optical disc 12.

To a terminal 1 of the signal recording apparatus is fed an analog videosignal, which is then converted by an analog-to-digital converter 2 intodigital video signals and thence supplied to an identification signalappendage circuit 3. To a terminal 28 can be sent a digital videosignal. When the digital video signal is supplied to the terminal 28, itis sent to the identification signal appendage circuit 3.

The identification signal appendage circuit 3 appends theabove-mentioned identification signal to the LSB of the eight bits ofthe luminance signals, as previously explained, under control by the CPU11.

The digital video signal, to which the identification signal has nowbeen appended, is sent to an encoding circuit 4. The encoding circuit 4encodes the digital video signal in accordance with the MPEG2 standardproposed by the MPEG (Moving Picture Image Coding Experts Group). Theresulting encoded signal is sent to a sector forming circuit 5.

The sector forming circuit 5 forms the encoded video signals intosectors in terms of a pre-set data quantity, such as 2048 bytes, as aunit, and appends error correction codes to the sectors. An output ofthe sector forming circuit 5 is sent to a header appendage circuit 6where header data arrayed at the leading end of each sector is appended.The resulting data is sent to an error correction coding circuit 7,which then executes data delay and parity calculations and appendsparity bits to the data.

An output of the error correction encoding circuit 7 is sent to amodulation circuit 8 which then converts the 8-bit data into, forexample, 16-channel bit modulated data, which is sent to asynchronization appendage circuit 9. The latter appends synchronizationsignals of a so-called out-of-rule pattern, violating the modulationrule of the above-mentioned pre-set modulation system, in terms of apre-set data volume as a unit, and sends the resulting data to arecording/reproducing head 14, via a driving circuit, that is a driver10.

The recording/reproducing head 14 performs recording and reproductionoptically, photomagnetically or by phase change, and records the abovesignals on an optical head run in rotation by a rotation servocontrolled spindle motor 13. The recording in this case includes notonly direct recording on the disc record medium, but also cutting fordisc production. For this cutting, pits are formed on a master disc,that is an original disc, a metal master or a stamper is formed byplating or the like, and an optical disc is then mass-produced usingthis stamper.

The optical disc 12 has a center aperture 102, and has, looking from theinner rim towards the outer rim thereof, a lead-in area 103 as a programmanagement area or table-of-contents (TOC) area, a program area 104, inwhich to record program data, and a program end area, that is aso-called lead-out area 105, as shown in FIG. 5.

With a signal reproducing apparatus for reproducing signals from theoptical disc 12, the optical disc 12 is run in rotation by the spindlemotor 13, and recording signals are read from the optical disc 12 by therecording/reproducing head 14. The signal read by therecording/reproducing head 14 (RF signals) are amplified by an amplifier15 and converted into bi-level signals by an RF processor 16.

The digital signal, converted by the RF processor 16 into bi-levelsignals, is sent to a synchronization separation circuit 17, which thenseparates the synchronization signal appended by the synchronizationappendage circuit 9. The digital signal from the synchronizationseparation circuit 17 is then sent to a demodulating circuit 18 forperforming a reverse operation of modulation performed by the modulationcircuit 8. The digital data from the demodulation circuit 18 is sent toan error correction decoding circuit 19 where the decoding which is thereverse operation of encoding by the encoding circuit 7 is performed.

An output of the error correction decoding circuit 19 is sent to asector resolution circuit 20 where it is resolved into sectors andsimultaneously corrected for errors. The resulting data is sent to anexpansion decoding circuit 21.

The expansion decoding circuit 21 decodes (expands) the encoded(compressed) video signals in accordance with the MPEG2 rule. Thedecoded (expanded) signals are sent to an identification signaldetection circuit 22.

The identification signal detection circuit 22 operates in associationwith identification signal addition by the identification signaladdition circuit 3 of the signal recording apparatus, that is, checksthe information of the LSB of the eight bits of the luminance signal, inorder to detect the identification signal appended to the LSB. Thedetected identification signal is sent to the CPU 25, which thenrecognizes the contents of the identification signal.

The digital video signal outputted by the identification signaldetection circuit 22 is sent to a digital/analog (D/A) converter 23where it is converted into analog video signals which are outputted atan output terminal 24. The digital video signal outputted by theidentification signal detection circuit 22 can be directly outputted tooutside via a terminal 29 without being sent to the D/A converter 23.

Although the structure of appending an identification signal to thedigital video signals upstream of the encoding circuit 4 is shown in theembodiment of FIG. 4, the identification signal can also be appended atthe time of encoding by the encoding circuit 4, as shown in FIG. 6.

Referring to FIG. 6, digital video signals outputted by the A/Dconverter 2, or digital video signals directly supplied from a terminal28 of FIG. 4, are directly supplied to the encoding circuit 4, to whichis annexed an identification signal detection circuit 36. The encodingcircuit 4 effects encoding in accordance with the MPEG2 as describedabove. The identification signal appendage circuit 36 appends theidentification signal to the encoded digital video signals under controlby the CPU 11 as will be explained subsequently. The digital videosignals, to which has been appended the identification signal, are sentvia a terminal 37 to a downstream circuit, that is the sector-formingcircuit 5 shown in FIG. 4.

The signal read out from the optical disc 12 and outputted from thesector resolution circuit 20 of FIG. 4 is sent via a terminal 38 to thedecoding circuit 21. The decoding circuit 21 has annexed thereto theidentification signal detection circuit 36. The identification signaldetection circuit 36 detects the identification signal appended to theencoded signal and sends the detected identification signal to the CPU2. The decoding circuit 21 performs decoding as described above. Anoutput of the decoding circuit 21 is directly outputted at a terminal 29of FIG. 4 or sent to a D/A converter 23 for conversion into analogsignals.

The encoding circuit 4 is configured as shown for example in FIG. 7.

Referring to FIG. 7, the digital video signal from the A/D converter 2of FIG. 6 or the digital video signal from the terminal 28 of FIG. 4 issupplied to a terminal 60. This digital video signal is supplied to asequence interchange circuit 61. The sequence interchange circuit 61designates one of the three picture types, namely an intra-picture(intra-coded picture), a predictive coded picture (P-picture) and abidirectionally predictive coded picture (B-picture), in terms of whichto process the pictures of the respective frames of the digital videosignals of the sequentially entered moving pictures, and re-arrays therespective frame pictures in the encoding sequence in accordance withthe designated types of the picture encoding. The sequence interchangecircuit 61 splits the video signals, re-arrayed on the frame basis andhaving a raster scan sequence video signals as shown by arrow SL in FIG.8a, into plural processing blocks MB, each composed of a plurality ofpixels G, as shown in FIG. 8b. The processing block MB is made up ofluminance components associated with 16 16 pixels. The luminancecomponents associated with 16 16 pixels are made up of four small blockseach made up of 8 8 dots, and are associated with Cb and Cr components,each made up of 8 8 dots. From the sequence interchange circuit 61, thepixel data in the processing block MB are taken out and outputted in thesequence shown by arrow S_(B).

An output data from the sequence interchange circuit 61 is sent to amotion vector detection circuit 73 for estimating the motion vector of acurrently encoded frame. The motion vector detection circuit 73 is alsofed from the sequence interchange circuit 61 with the informationspecifying the picture encoding type synchronized with each frame, sothat data of the respective frames are processed as I-picture, P-pictureor B-picture in accordance with the picture encoding type information.That is, the motion vector detection circuit 73 generates the motionvector information using the picture encoding type and the predictionerror data from a frame memory 71 as later explained. An output of themotion vector detection circuit 73 is sent to a motion compensationprediction circuit 72.

The motion compensation prediction circuit 72 generates a predictionpicture, using the picture encoding type information, motion vectorinformation and prediction error data from the frame memory 71. Noprediction picture is generated for the I-picture. The predictionpicture data is sent to a subtractor 62 and to an adder 70.

The subtractor 62 subtracts data of the prediction picture form dataoutputted by the sequence interchange circuit 61 to produce differencedata which is outputted as prediction error data. If the data of a frameto be processed as an I-picture is supplied from the sequenceinterchange circuit 61, no subtraction is carried out, such that data ofthe frame is directly outputted.

An output data of the subtractor 62 is sent to an orthogonal transformcircuit 63 executing a discrete cosine transform (DCT). The DCTcoefficients resulting from DCT processing are sent to a quantizationcircuit 64.

The quantization circuit 64 performs non-linear quantization on the DCTcoefficients with a quantization scale (quantization step) associatedwith the prediction error data and outputs the resulting quantized data.That is, the quantization circuit 64 performs non-linear quantizationusing a finer quantization step and a coarser quantization step if theprediction error data is close to zero or if the absolute value of theprediction error data is larger, respectively. The quantization circuit64 also quantizes the DCT coefficients with the quantization scale(quantization step) associated with the data storage quantity in abuffer memory 66 of a succeeding stage.

The quantized data outputted by the quantization circuit 64 is sent to avariable length encoding circuit (VLC) 65. This variable length encodingcircuit 65 converts quantization data from the quantization circuit 64into, for example, a variable length code, such as a Huffman code, inassociation with the quantization scale information supplied from thequantization circuit 64, and outputs the resulting code to the buffermemory 66. The variable length coding circuit 65 also variable lengthencodes the information specifying the picture encoding type, theinformation specifying the quantization scale, the prediction modeinformation from the motion vector detection circuit 72 and the motionvector information.

The buffer memory 66 transiently stores data supplied from the variablelength encoding circuit 65. The data thus stored is subsequently readout at a pre-set timing so as to be outputted at an output terminal 67.Output data from the output terminal 67 is sent via terminal 37 of FIG.6 to the sector forming circuit 5 of FIG. 4. The buffer memory 66 feedsback the quantization control signal associated with the data storagequantity to the quantization circuit 64. That is, if the residual storeddata quantity is increased to an allowable upper limit value, the buffermemory 66 causes the quantization scale of the quantization circuit 64to be enlarged by the quantization control signal for lowering the dataquantity of the quantized data. On the other hand, if the residualstored data quantity is decreased to an allowable lower limit value, thebuffer memory 66 causes the quantization scale of the quantizationcircuit 64 to be diminished by the quantization control signal forincreasing the data quantity of the quantized data. This preventsoverflow or underflow of the buffer memory 66.

On the other hand, output data of the quantization circuit 64 issupplied to a dequantization circuit 68 where dequantization occursusing the quantization scale information supplied from the quantizationcircuit 64. Output data of the dequantization circuit 68 is sent to aninverse orthogonal transform circuit 69 where it is inverse DCTed andstored via an adder 70 in a frame memory 71.

The data read out from the frame memory 71 is sent to a motioncompensation prediction circuit 72, where a prediction picture isgenerated using the data read out from the frame memory 71, the pictureencoding type information and the motion vector information, asexplained previously.

The data outputted by the sector resolution circuit 20 and sent viaterminal 38 of FIG. 6 is sent to a terminal 80 of the decoding circuit21 of FIG. 21. This data is transiently stored in a buffer memory 81 andsubsequently read out from the buffer memory 81 so as to be sent to avariable length decoding (VLD) circuit 82.

The variable length decoding (VLD) circuit 82 decodes the data suppliedfrom the buffer memory 81 by a decoding operation corresponding to thevariable length encoding at the time of encoding the moving picture. Theinformation on the quantized data and the quantization scale(quantization step) resulting from the decoding by the variable lengthdecoding circuit 82 is supplied to a dequantization circuit 83. Thevariable length decoding circuit 82 also decodes the informationspecifying the picture encoding type, motion compensation modeinformation and the motion vector information and sends the resultinginformation to a motion compensation circuit 86.

The dequantization circuit 83 dequantizes the quantization data suppliedfrom the variable length decoding circuit 82 in accordance with thequantization scale information supplied from the variable lengthdecoding circuit 82 and sends the dequantized data to an inverseorthogonal transform circuit 84.

The inverse orthogonal transform circuit 84 performs inverse DCT (IDCT)on data supplied from the inverse quantization circuit 83. Output dataof the inverse orthogonal transform circuit 84 is sent to an adder 85.

The motion compensation circuit 86 has a frame memory in which picturedata resulting from previous decoding is stored. The motion compensationcircuit 86 generates reference picture data from the decoded picturedata stored in the frame memory, based on the motion compensation modeinformation and the motion vector information, and outputs the referencepicture data to the adder 85. The adder 85 adds the output data of theinverse orthogonal transform circuit 84 (difference data in case of Pand B pictures) to the reference picture data. If the picture beingprocessed is an I-picture, no reference picture data is generated in themotion compensation circuit 86, so that the reference data is not addedto the picture data by the adder 85.

The identification signal addition circuit 35 of FIG. 6 sends anidentification signal to the above-described encoding circuit 4configured as shown in FIG. 7. The encoding circuit 4 appends anidentification signal to data resulting from processing by theorthogonal transform circuit 63, quantization circuit 64 or the variablelength encoding circuit 65 in a manner of minimizing adverse effects onthe data. The identification signal detection circuit 36 detects theidentification signal appended to the data resulting from processing bythe orthogonal transform circuit 63, quantization circuit 64 or thevariable length encoding circuit 65.

The structure of FIG. 6, having the orthogonal transform circuit 63 andthe inverse orthogonal transform circuit 84, adds the identificationsignal as follows:

Suppose that there are n pixels in the vertical direction and m pixelsin the horizontal direction. In DCT, usually n=8 and m=8. Ifdeterminants [Y], [X], [Dn] and [Dm] shown in Equations 1 to 4 are used,data made up of n pixels in the vertical direction and m pixels in thehorizontal direction, as indicated by a determinant [X], are convertedby DCT as orthogonal transform into coefficient data represented by thedeterminant [Y] by transformation matrices [Dn] and [Dm] as shown by anEquation (5): $\begin{matrix}{\lbrack Y\rbrack = \begin{bmatrix}y_{0,0} & y_{0,1} & \ldots & y_{0,{m - 1}} \\\vdots & \quad & \quad & \vdots \\y_{{n - 1},0} & \ldots & \ldots & y_{{n - 1},{m - 1}}\end{bmatrix}} & (1) \\{\lbrack X\rbrack = \begin{bmatrix}x_{0,0} & x_{0,1} & \ldots & x_{0,{m - 1}} \\\vdots & \quad & \quad & \vdots \\x_{{n - 1},0} & \ldots & \ldots & x_{{n - 1},{m - 1}}\end{bmatrix}} & (2) \\{\left\lbrack D_{n} \right\rbrack = \begin{bmatrix}d_{0,0} & d_{0,1} & \ldots & d_{0,{n - 1}} \\\vdots & \quad & \quad & \vdots \\d_{{n - 1},0} & \ldots & \ldots & d_{{n - 1},{n - 1}}\end{bmatrix}} & (3) \\{\left\lbrack D_{m} \right\rbrack = \begin{bmatrix}d_{0,0} & d_{0,1} & \ldots & d_{0,{m - 1}} \\\vdots & \quad & \quad & \vdots \\d_{{m - 1},0} & \ldots & \ldots & d_{{m - 1},{m - 1}}\end{bmatrix}} & (4)\end{matrix}$

 [Y]=[Dn][X][Dm] ^(T)  (5)

On the other hand, the transform shown by the equation (6):

[X]=[Dn] ^(T) [X][Dm]  (6)

is executed in an inverse orthogonal transform associated with theorthogonal transform.

As characteristic of DCT, the inverse matrix is equal to the transposedmatrix, as indicated by the equations (7) and (8):

[Dn] ⁻¹ =[Dn] ^(T)  (7)

[Dm] ⁻¹ =[Dm] ^(T)  (8)

In the above-mentioned orthogonal transform and inverse orthogonaltransform for DCT with n pixels in the vertical direction and m pixelsin the horizontal direction, it is the 64th DCT coefficient, that is thecoefficient of the eighth row eighth column, that remains affected tothe least extent by addition of the identification signal. theidentification signal.

Therefore, if the identification signal is added to the DCT coefficientobtained by the processing by the orthogonal transform circuit 63 ofFIG. 7, the identification signal addition circuit 35 adds theidentification signal to data of the 64th of the DCT coefficients. Onthe other hand, if the identification signal is added to the quantizeddata obtained by the processing by the quantization circuit 64, theidentification signal addition circuit 35 adds the identification signalto the quantized data corresponding to the 64th DCT coefficient.Similarly, if the identification signal is added to the quantized dataobtained by the processing by the variable length encoding circuit 65,the identification signal addition circuit 35 adds the identificationsignal to the quantized data corresponding to the 64th DCT coefficient.If such addition of the identification signal is done, theidentification signal detection circuit 36 detects an identificationsignal added to one of the DCT coefficient data, quantized data andencoded data.

Of course, the identification signal can be added not only in anupstream area of the encoding circuit 4 or in the course of encoding,but also in a downstream area of the encoding circuit 4. In addition,signal recording includes not only direct recording on a record mediumbut also mass producing recorded media by cutting a master disc for massproduction or with the aid of cut master discs.

Although the identification signal is added in the above examples to thedigital video signal, it is also possible to add or multiplex anidentification signal to video signals in the analog stage, as shown inFIG. 9.

Referring to FIG. 9, an analog video signal supplied to the terminal 1is sent to an identification multiplexing circuit 30. The identificationmultiplexing circuit 30 multiplexes the identification signal on theanalog video signal under control by the CPU 11.

For multiplexing the identification signal on the analog video signal,such a method may be employed in which a signal coded in plural bits ismixed by frequency multiplexing in a pre-set horizontal period of theanalog video signal. Meanwhile, the identification signal coded withplural bits is comprised of, for example, 14 bits of data and 6 bits oferror detection codes (CRCC), and may be inserted in 22nd horizontalperiod for an odd fields and in the 285th horizontal period for an evenfield.

The analog video signal, whose identification signal has beenmultiplexed by the identification signal multiplexing circuit 30, isconverted by the A/D converter 2 into digital video signals which arethen sent to the encoding circuit 4. The signals encoded by the encodingcircuit 4 are sent via a terminal 31 to a downstream side circuit, thatis to the sector forming circuit 5 shown in FIG. 4.

The signal read out from the optical disc and outputted from the sectorresolution circuit 20 of FIG. 4 is sent va terminal 32 of FIG. 9 to adecoding circuit 21. The signal decoded by the decoding circuit 21 isconverted into analog video signals by the D/A converter 23 so as to besupplied to the identification signal detection circuit 33.

The identification signal detection circuit 33 detects theidentification signal multiplexed on the analog video signal and sendsthe detected identification signal to the CPU 25. The analog videosignals from the identification signal detection circuit 36 is outputtedvia output terminal 24 to outside.

For adding the identification signal to an analog audio signal, astructure shown in FIG. 10 may be employed.

Referring to FIG. 10, analog audio signals supplied via terminal 40 isamplified by a line amplifier 41 and thence supplied to theidentification signal addition circuit 42. The identification signaladdition circuit 42 adds the identification signal to the analog audiosignal under control by the CPU 48.

The identification signal added to the analog audio signals may be aso-called dither noise to which the meaning as an identification signalhas been accorded. The dither noise is the high-frequency quantizationnoise generated in the downstream side quantization and previouslysuperimposed on the analog audio signal for psychoacoustic noisereduction. This dither noise is modulated by FM or AM so as to be giventhe meaning of the identification signal and the resultingidentification signal is added to the analog audio signal.

The dither noise, given the meaning of the identification signal, isgenerated by the dither generating circuit 47 under control by the CPU48, and is added to the analog video signal by the identification signaladdition circuit 42.

An output of the identification signal addition circuit 42 is sent viathe low-pass filter 43 and the sample-and-hold circuit 44 to the A/Dconverter 45 where it is converted into a digital audio signal. Thedigital audio signal is sent via terminal 46 to a downstream sideoptical disc recording system. Since the recording system issubstantially similar to the recording system shown in FIG. 4, it is notexplained for clarity.

The audio signal recorded on the optical disc is reproduced as by thereproducing system and sent via a terminal 49 to a D/A converter 50. Thereproducing system also is similar to the reproducing system shown inFIG. 4 and hence is not explained in detail. The analog audio signalfrom the D/A converter 50 is sent via a low-pass filter 51 to anidentification signal separation circuit 52.

The identification signal separation circuit 52 separates the dithernoise, given the meaning as the identification signal, from the analogaudio signal, and sends the separated signal to a dither analysiscircuit 55. The dither analysis circuit 55 analyzes the dither noise andextracts the identification signal to send the extracted identificationsignal to a CPU 56, which then judges the contents of the identificationsignal.

The analog audio signal from the separation circuit is amplified by aline amplifier 53 so as to be outputted to outside via a terminal 54.

By previously modulating the dither noise added to the analog audiosignal in accordance with the identification signal, the identificationsignal can be inserted into the audio signal itself while the effect onthe analog audio signal is minimized. The signal to which is added theidentification signal is not limited to the analog audio signal but mayalso be an analog video signal. In addition, the signal to which isadded the dither signal is not limited to the analog signal. Thus thedither signal added to the multi-bit digital signal prior tore-quantization may be modulated in accordance with the identificationsignal.

In the above-described structure of the present invention, encoding inaccordance with the MPEG2 standard is explained as an example. However,the present invention may also be applied to encoding in accordance withthe MPEG1 standard or encoding by generic subband coding, predictivecoding, orthogonal transform coding or encoding by vector quantization.In the field of audio signals, the present invention may similarly beapplied to encoding known as adaptive transform acoustic coding (ATRAC)which takes human psychoacoustic characteristics into account. The videosignals may be still pictures, graphics pictures or letters, in additionto usual moving picture signals.

As for the signal record medium, an optical disc on which recording canbe done by pits, a write-once optical disc, an overwritablemagneto-optical disc, a phase-change type optical disc, an organic dyeoptical disc, an optical disc on which recording can be done with an UVlaser beam or an optical disc having a multi-layer recording film, canbe employed as an optical disc. In addition, a tape-shaped recordmedium, such as a video tape, a semi-conductor record medium, such as anIC card or a variety of memory devices, or a magnetic disc recordmedium, such as a hard disc or a flexible disc, may also be employed.

If the method of appending the identification signal as proposed by thepresent invention is used, not only the signal can be identified asdescribed above, but also unauthorized signal copying can also beprohibited. That is, it becomes possible to prohibit data recorded on asignal record medium, such as an optical disc, from being copied on arecordable and reproducible record medium, such as a hard disc, while italso becomes possible to prohibit copying from another record mediumobtained by directly copying data recorded on the hard disc.

For example, in a duplicating device in which video or audio signals,read out from a signal record medium, are recorded in a plurality ofother signal recording media, identification signals are added to videoor audio signals to which the above-mentioned identification signals arenot added, while the video or audio signals to which the identificationsignals have been added are prohibited from being copied. In this case,it is possible with the duplicating device to record on a separate discor the like such signals read out from a regular master disc or mastertape having recorded thereon original video signals or audio signals towhich no identification signal has been added. On the other hand, it ispossible with the duplicating device that signals read out from a disc,having recorded thereon these signals to which the identification signalhas already been appended, be recorded on another record medium,provided that the duplicating device detects such identification signal.

As a method for prohibiting unauthorized copying, it has been practicedto record ciphered signals on the signal record medium. However, thesignal can be copied freely after deciphering. If, however, theidentification signal is added to the signal itself, as in the presentinvention, unauthorized copying can be prohibited as described above inthe duplicating device.

The identification signal can be a copy inhibiting signal, a plant ID, aproducer ID, or a key for encryption. Since the identification signal isadded as the information of “0” or “1” to the signal itself, it cannotbe modified easily, so that it is highly useful for copying prohibition.

If the identification signal is appended on the time basis, if the timeis of short duration, such as {fraction (1/30)} second, theidentification signal can be detected easily when the signal is detectedlater. If the time is of long duration, the identification signal canhardly be detected, meaning that alteration of the identification signalcan hardly be achieved. If the identification signal is added at ansynchronous timing, the identification signal cannot be detected easily.

In the above-described embodiment, signals are recorded or reproduced onor from a signal record medium. It is however possible to add theidentification signal to the transmission/reception signal as describedabove at the time of signal transmission and reception using a signaltransmission medium such as a telephone network, light cable orelectrical waves for radio communication not only for groundcommunication but also for satellite communication. The favorable effectof the present invention may also be achieved when the identificationsignal is added to the transmission/reception signal.

As an illustrative structure of signal transmission and reception,signal transmission and reception may be configured as shown for examplein FIGS. 11 and 12 showing the structure of a transmission system andthe structure of a reception system, respectively.

Referring to FIG. 11, showing a transmission system, digital videosignals and digital audio signals are supplied to a terminal 200. Thesignals supplied to the terminal 200 are sent to an encoding circuit 201where the signals are encoded as described above in connection with FIG.4. The encoding circuit 201 has annexed thereto an identification signaladdition circuit 202. The identification signal from the identificationsignal addition circuit 202 is added to the video signal or audiosignals as described above. The signal added to with the identificationsignal is outputted at the encoding circuit 201. The encoded signal fromhe encoding circuit 201 is sent to a modulation circuit 203 where it ismodulated by pre-set digital modulation. The modulated signal is sent toa mixing circuit 204 comprised of, for example, a linear multiplier. Themixing circuit 204 is fed with a transmission carrier frequency signalfrom a transmission frequency generating circuit 205, so that thetransmission carrier frequency signal is modulated by the signal fromthe modulation circuit 203. The transmission signal of the transmissionfrequency range, outputted by the mixing circuit 204, is amplified to apre-set level by a transmission amplifier, and transmitted over anantenna 207.

In the reception system, shown in FIG. 12, the signal received by anantenna 300 is amplified to a pre-set level by a reception amplifier301. An output signal of the reception amplifier is sent to a mixingcircuit 302. The mixing circuit 302 is fed with a reception frequencysignal phase-synchronized with the carrier wave from the receptionfrequency generating circuit 303 so that a modulation signals of thecarrier wave, that is reception signals, are taken out by synchronousdetection by the mixing circuit 302. An output signal of the mixingcircuit 302 is sent to a demodulation circuit 304 where an operationwhich is the reverse of the modulation by the modulation circuit 203 ofthe transmission system is carried out. The signal taken out fromdemodulation is sent to a decoding circuit 305 where decoding which isthe reverse of the encoding by the encoding circuit 201 of themodulation system is carried out. The decoding circuit 305 has annexedthereto an identification signal detection circuit 306 where theidentification signal is detected in the same manner as described above.The signal decoded by the decoding circuit 305 is outputted at aterminal 307.

FIG. 13 shows an illustrative structure for transmitting/receivingsignal over a telephone network or an optical cable. To a terminal 400of FIG. 13, there is supplied a signal encoded and outputted by themodulation circuit 8 as described above. The signal supplied to theterminal 400 is sent from a transmission interfacing device 401 of thetransmission system to a transmission path 402. The signal transmittedon the transmission path 402 is sent via a transmission interfacingdevice 403 of the reception system to a terminal 404. The signalsupplied to the terminal 404 is sent to an arrangement downstream of thedemodulating circuit 18 shown in FIG. 4.

It is to be noted that the above-described transmission/reception may beapplied not only to an analog system but also to a digital system.

What is claimed is:
 1. A signal record medium having recorded thereon avideo signal and/or an audio signal of which a least significant bit ofa plurality of portions of said video signal, and/or said audio signalhas been modified to include an identification relevant to said videosignal and/or said audio signal within a portion of said video signaland/or said audio signal including, or in the vicinity of, a determinedhigh level portion thereof within a predetermined time interval, and ina configuration so as to reduce the effects of the inclusion of saididentification on said video signal and/or said audio signal, andwherein said identification is detected by an apparatus that separatessaid identification from said video signal and/or said audio signal bysampling all of the least significant bits of all of the video signaland/or audio signal in said predetermined time interval and processingall of said detected least significant bits.
 2. The signal record mediumas claimed in claim 1 wherein said video signal and/or said audio signalis modified to include said identification in a configuration so thatsaid identification is detected by statistic processing of said videosignal and/or said audio signal.
 3. The signal record medium as claimedin claim 2 wherein a least significant bit of a portion of said videosignal and/or said audio signal is modified to include saididentification.
 4. The signal record medium as claimed in claim 3wherein said identification is inserted into said video signal and/orsaid audio signal having a high signal energy.
 5. The signal recordmedium as claimed in claim 2 wherein said identification is included insaid video signal and/or said audio signal at a synchronous timing. 6.The signal record medium as claimed in claim 2 wherein saididentification is included in said video signal and/or said audio signalat an asynchronous timing.
 7. The signal record medium as claimed inclaim 1 wherein a least significant bit of a pre-set sample of saidvideo signal and/or said audio signal having a high signal energy ismodified to include said identification.
 8. The signal record medium asclaimed in claim 7 wherein said identification is inserted into saidvideo signal and/or said audio signal having a high signal energy. 9.The signal record medium as claimed in claim 1 wherein said audio signaland/or said video signal is modified to include said identificationsignal at a synchronous timing.
 10. The signal record medium as claimedin claim 1 wherein said video signal and or said audio signal arecompressed signals.
 11. The signal record medium as claimed in claim 1wherein said identification is arrayed at a higher coefficient positionof the coefficients obtained on orthogonal transform of said videosignal and/or said audio signal.
 12. The signal record medium as claimedin claim 1 wherein a dither noise modulated in accordance with theidentification is added to said video signal and/or said audio signaland the resulting signals are recorded on the signal recording medium.13. The signal recording medium of claim 1, wherein said portion of saidvideo signal and/or said audio signal including, or in the vicinity of,said high level portion has been modified by increasing the values ofsaid video signal and/or said audio signal, decreasing the values ofsaid video signal and/or said audio signal, or keeping the values ofsaid video signal and/or said audio signal without change.
 14. Thesignal recording medium of claim 1, wherein said identification has beeninserted in a least significant bit of a plurality of portions of saidvideo and/or audio signal at predetermined portions of said video and/oraudio signals, said identification defining that said video and/or audiosignal is original or copied, a maker identification, a formatteridentification, or copying management information.